Cable reeling mechanism



Oct. 6, 1953 Original Filed May 1, 1948 R. J. HOPKINS CABLE REELING MECHANISM 4 Sheets-Sheet l jmmrdJ/ opmk 9 4m; A mm any.

Oct. 6, 1953 R. J. HOPKINS 2,654,548

CABLE REELING MECHANISM Original Filed May 1, 1948 v4 Sheets-Sheet 3 Z V .Zhuenfar: 55 azardJfia hm.

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R. J. HOPKINS CABLE REELING MECHANISM Oct. 6, 1953 Original Filed May 1, 1948 4 Sheets-Sheet 4 5 m mmnxnmm. Mg m 4 b i a m W M r: w g E a N am. A, w v m &\\ m M v M y fl. 7 2 7 9 w a a 2 M V K M... f 7///////% I 1 m 2 W w i atentecl Oct. 6, 1953 ,7 UNITED STATES PiQTENT UFFICE Kauai-ii FEELING MECHANISM Joy5Man ifz i'cfi ng Companj', Pittsbuigli, Pa., 2. onsaraiian of Pennsylvania Ciiiffiniiitifi-fif 'iipfilic'atibh S'e'fifl NO: 24558; May 1*,1'1'948. This application February '25, 1953*;Seri2-1 N 338;? 90 i rs'oiaiiiisi (o1. zip- 30) tr ae a mipwaeaaaa "ailin an P g 9. 12"m all ll i i ii l y adapted for use on mine vehicles, and frorn this aspect relates especially to a iluid motor drills n r l ppar il s lfqraeabler 5 which wqu' d he which! whic mw i supplied to a self-propelledvehicle such as ashutrti c o mine ecfem tiveb the thrii t re m iwi I6 VI- Ffrom another aspect, it relates to control valve apparatus ludin'ga' pl'uralit of mechanisms per se val'v'es, "a hydraulically controlled I fe dem bfiimeht viif tlli 'iiv itib -,shiit rvalvs i r rend ns Qila h j r of from its reelingmechanism aspegt the same may the r-chef devicesje'ffeg v e'tocfontrol' the pressures comprise a source of hydraulic fluid, pump in a line b t t u a d mete numbnewhose drive is independent of; the; propulsion of vice, andnf eans forprovidifiig a 'sharpand deli. the vehicle with which-themechanism mav be 15 nite movement of 'tl'i'e -shifte'r valve regardless used, a motor-pump; device operativelyconnected t to a cable reel s o that neithei can-turn without the turningof the; other, and an automatic valve mechanism includingvalves -respectively opera- I tive to determinethe-pressureimposed on the dev r H H -pu d i w e the c bl bein ri 't'ar h t o said relief wound in and operative to determine the D36 devicesff fective' to or'lt l the r ss ure in a line pressure imposed onthe motor-pump device between thefiulnplandth ma pr-pump-devme, when the cable is beingpayedout, anautomatic dependentupon thejdirection of rotation ofth'e shifter valve controlled-at least inpart by the latter, and to provide an autoinatik: establishpressures built up by; the motor-pump device Irient o'f control by the relief devic'elhavingth'e when the same is acting as a pump; for shifting higher" pr'omp y upon the coming to a connections insuch amanner that;-whereas-dur stop of the qrump dviceronowing apeing winding in of; the cable; the relief device has ofopera as ump; and 'a control for having a higher setting is in-control; yet there'- t shifte flvalve prov n'ganimproved operaliefdevice having the lowersetting shallbe tion hereof. 'Qthr Je'ts'and advantage's of come operative when cableis pulled Qfi-ofthe the'inventibnwill her. ff te r morefiilly appear. reel, and that the main pump discharge shall Referring to d fa, i'rigs iniwliich' a preferred beautomatically relieved; ofsubstantially all t (1 two' modifications of my inback pressure,- and means associated with; the shifter valve forinsuring the sharp throwing thereof; A v, I

From its control-valve aspect the-invent-ion,;in a preferred embodiment, may compriseia casing providing chambers having in them respectively a shifter valve, two'relief valves, anda check valve, an external inlet connection having communication with one end of said; shifter valve containing chamber and also with:v that chainher at a point betweenthdends'ofithe latter and also with said check-valve and with one" of-ysaid relief valves, an external verit connedtioni'cou'l municating with the chainbers'cdnt'aining'"eachof said relief valvesa'nd-with said shifter valve containing chamber ata-difierehtpoint' betweenthe ends of the latter, a'conhc-tiori between the other relief valve and said-shifterv'alve: containing W I A chamber at'another point-between'the ends of 999101 valye ,.gpec ,an p, V iiion Corr? thelatter, a thirdexternalconnectioncommunisp ngling to that ofFig 1, but the scale: bein eatin with'the: ":f i; f: ale s iit r xa v larger c chamber t sa check alve 29 tam n chamber, and meansf onnecting toge opposite ends of said shiftervalve conta g chamber oiily'wl'i'n pnei iirti 'vaiv is"at; st

I illustrating [a e s" associated I with ap'reir ivin p deviceoperativelv view or chef and 11 ii/r1; in Fig; 1', the t; might be called the h drawings; v

N relief and control phejiew being from View the rag. f1, through Ibe'rs I6 and l8 may be arranged in line with each other, as shown in Figs. and 7, and separated ..by a ported septum as which provides a valve Figs. 5 and '7, showing the shifter valve in still another position, the right hand portion of the valve mechanism being broken away.

Fig. 9 is a fragmentary sectional view taken on the plane of the line 99 of Fig.5.

Figs. 10 and 11 are views similar to Fig. l, butshowing the relief and bypass valvemechanism in a developed or schematic manner so that all of the passages therethrough and elements thereof may be noted in their working operations.

Fig. 12 is an enlarged sectional view on a plane corresponding to the plane of the section line 55 of Fig. 4, showing a modified relief and control valve mechanism.

Fig. 13 is a sectional view on the same plane and scale as Fig. 12, with parts shown in different relative positions.

Fig. 14 is an enlarged sectional view of another modified form of relief and control valve mechanism, this view also being taken on a plane corresponding to the plane of section line 55 of Fig. 4.

Fig. 15 is :a sectional view on the same plane and scale as Fig. 14, with parts shown in different relative positions.

Referring now to the drawings, and first to Figs. 1, 10 and 11, it will be noted that a reservoir or tank I constituting a source of hydraulic fluid is provided to contain the necessary quantity of such fluid for the driving and controlling of the reel. It may, of course, constitute a source of fluid for other purposes, but with that we are not here concerned. The reservoir is connected by a suction line 2 with a main pump 3, which is driven from any suitable source of power, not shown, and which is desirably driven whenever power is being delivered to the vehicle (not shown) on which the reel is supported. The pump 3 delivers fluid under pressure to a line 4 which is connected with a relief and shifter valve mechanism generally designated 5; which has a connection 6 leading to 'a motor-pump device I. This motor-pump device 1 is operatively connected as by a belt or chain 8 with a cable reel 9 upon which .a power supply cable It is wound. While my invention is specifically described with reference to a cable reel carrying an electric cable for supplying current to electric motors, the invention is not limited to such systems, but includes within its contemplation reels for flexible conductors for other operating media. The motor-pump. device I is connected with a conduit whichleads back to the reservoir or source and a relief line l3 leads from the valve mechanism 5 to the line I The. pump 3 is shown as the intermeshing gear type, as is also the motor-pump device I. The specific details of the construction of the pump and motorpump device, and even the types thereof, are not essential to the invention, and such devices are so well known per se that they are not more extensively illustrated.

The valve mechanism 5 provides a chamber Hi to which hydraulic fluid is delivered by the conduit 4. From the chamber I5 fiuid may be delivered through a shifter valve chamber I! to the connection l3 leading to the source or, as will shortly be explained, to another chamber l8 which is connected with the conduit 6 leading to the motor-pump device 1 and which communicates also with the shifter valve chamber H as will later be described. Desirably, the chamseat 2| which a check valve 22 is adapted to engage and against which said check valve is adapted normally to be maintained by a spring 23 which at one end engages the check valve and at its other end rests upon a plug 24 with which the conduit Bis threadedly or otherwise suitably connected. The chamber |5 communicates with the chamber N3, of course, when the check valve 22 is unseated. Fig. 9 will aid in the comprehension of the structure of the check valve '22, and from this figure. it will be noted that the valve has a number of slots 25 in its periphery through which fluid may flow from the chamber It to the chamber |8 when the valve 22 is unseated. r

The shifter valve receiving chamber ll includes five annular chambers, each spaced from the next adjacent chamber by a ported partition. Starting from the top in Fig. 5, these annular chambers are successively numbered 25, 21, 28, 29 and 30. A ported partition 3| separates the chambers 26 and 21. A ported partition 32 separates the chambers 21 and 28. In like manner, ported partitions 33 and 34 respectively separate the chambers 28 and 29 and the chambers 29 and 36. Each of the ported partitions has the port therethrough of the same size as each of the others, said several ports being coaxially arranged so that their surrounding walls provide guidance for a two-spooled shifter valve 36 comprising an upper hollow spool 31, a lower spool 38 and a connecting portion 39 of reduced diameter, by reason of which an annular fluid conducting groove 45 is provided between the spools 3'! and 38, and a ported stop projection 4|. The spool 31 has a chamber or recess 42 in it, and a spring 43 extends into the recess and engages the lower end of the latter, the upper end of said spring 43 contacting an abutment plug 44 suitably packed at 45 to prevent leakage. A port 45, of relatively small diameter at its lower end 4! where it extends through the stop projection 4|, connects the chamber 42 in certain positions of the shifter valve with the space surrounding the stop projection 6|. In other words, it connects the chambers 26 and 39, when open. The stop projection 4| of the valve is adapted to cooperate with a, suitable abutment plug 48 and with a yieldingly mounted valve 49, of which more will be said shortly. The abut- .ment plug limits the downward. movement of the shifter valve and the valve maintains closed the passage 46, 41 during its engagement with the projection 4|.

The annular chamber 25 communicates with the chamber l6 through a port or cored opening 50. Similarly, the annular space 2? communicates through a port or cored opening 5| with the chamber |6. Annular chamber 28 communicates through the conduit l3 with the conduit leading'to the fluid source or reservoir The annular chamber 29 communicates through a port or opening 52 with the chamber 53 in a relief valve casing 54 shown in the drawings as a separate element from the main body of the valve 'mechanism as a whole, but obviously formable 5, through an opening 59 wi-th" aehambr; GII'in-the relief valve casing 54} The annular chamber 26 communicates through an opening 613 with a chamber 62' in the relief valve housing: 58 The chamber 53' is separated from v the" chamber 60' by a ported valve seat 64 with which a; spring pressed relief valve? 65' is adapted to" cooperate; A spring 86 having: a follower 61 is adjustably loaded by an adjusting screw and nut mechanism 68', which controls-the compression of the' spring" 66 and thus determinesthepressur'e at.- which the valve 65 will lift fromthe seat 64: A valve seat- 69 surrounding a-port- 1:0 extending between the chambers 51 and 62 i'sadapted'to'be engaged by a relief valve Tl pressed in a closing direction by a spring 72 which engages a" follower 13 whose position may beadjusted by' a suitable screw andnut mechanism 1'4: The:valve's 65 and H have flow-slots in then'ian'ne'r of valve'2'2z It will be observed that when thevalve' 36 isintop position; it does not prevent communicationbetween the chamber I6 and the port 10: The normal compression of the spring" 12 will bemuch higher than the normal compression of the spring 66, when their controlling valves have equal areas subjected to pressures tending to unseat such valves. For example,.it may require-'aliquid'p'ressure of 300 p. s. i. in chamber 62 to unseat valve H', while for example a pressure of- 100'p; s. i. in chamber 53 will suifice t'o unseat'valve 65;

The valve 49 consistsof a head portion-l and a plunger portion It; the head portion being slidably received in a chamber: Tl formedin the abutment plug 48 and the plunger portion T6 extending through a" reduced opening 18* coaxial with thechamber ll. A spring 19 engages the head portion at one endta'nd at-its other end engages an adjustable threaded follower 80; and the pressure exerted by' the spring 19 may be determined by the adjustmentof its follower 80. Normally the spring 19" tends to maintain the plunger 16- inthe position showirin -Fign'l, but the valve fill-may be depressed to" the position shown in Figs; 5 and-6 and the' phmger portion 16 is adapted to-seal-the' opening ih-the-several positions of the shifter valve illustrated in'Figsi 5; Sand 8', but doesn'ot seal the dpehiiig 41 i'n the' position of the shiftervalve shown i'n -Fig. '7-.- It may further be noted thatsealing of the opening 41' by the'plun'g-er' portion" m -willbe discontinued as" the-shifter vaive st-meves upward; only; with the proportions shown; when the shifter valve reaches a position at which the save of fluid through the port 5 1' and through the annular recess or groove 28 and the cbnneetion 13 has commenced. This means that the shift will be sharply thrown; as the press upper endwilldrop"when= chaniber It eon nected with vent line t3; The mode ofoper'ation of'the valve element 4-9and1its cooperation with the other parts of the mechanism will I be more fully explained shortly. V

The pump 3 may becon'sidered', forthe purposes of explaining" the'mode ofoperation ofthe invention, tobe driven continuously while the vehicle is in use; Accordingly, it? is tahihg liquid from the reservoir or'source' I, through the conduit 2, and dischargingit throughthe conduit 4 into the chamber [6; and the fluid that enters the chamber I8 mustobviously go somewhere. Some of it can go through the conduit 6- after passing the check valve 22; and cause-the motorpu'mpdevice I to operate as amotor'and-efiect awi'nding in of the cable [0, and then' pass back to the source I through the conduit II, if the cable can be reeled However, the rate at which the cable can" be-wounddn -may' and-- prob-- ably will be" entirely insufiicient to-permit all of the fluid delivered by the pump 3'to-pass throughthe motor-pump device 1 and,,. indeed; it is pos sible that the-motonpu-mp device may be entirely incapable of winding in the cable at all, aswhen the vehicle isat'astandstill. Therefore, some-of the liquid delivered to'the chamber IE5 must go elsewhere,. and thisitwill do, passing by way of the passage 50 the annulargroove Zfiyth'e passage 61', the chamber 62; the port 10-, past the reliefvalve H, through-the chamber 51*, the port 56; the-groove'28; and the conduit'l-3'into'the return line I l and back to the source or' reservoir I. The pressure of the spring 12' willbe made sufficient-to compel the desired pressure to be maintained in the chamber lt andin the'condu-it 6: For example, a pressureof-BUO p. s; i; may be main-- tained in the fluid-supply connections to the motor-pump device 7' by the appropriate setting: of the spring 12-.- In Figs.- 10 and-1l, it may be; noted that inorder to avoidoverlapping ports the connection of the conduit I3=with-thechamber'28 is shown as made by way ofa" portion of the port 56 instead or opening into=the-chamber ZB-separately from the port 56 and'at rightangles; to the communication of'that port with the chamber 28. Fig. 11, subject to-theunderstand-ing just, expressed, may be considered to show' the normal-v position of the parts during: the operation of the. motor-pump device 1' as amotor toeffectwinding: in of the cable I0; in-other WOldS;-- the modeofj operation which-takesplace when the vehicleis: moving in a direction 1 to shorten the free length of the cable. Atthistime-the shifter valve-36- occupies the position 'shown-in Figs-r 5 and'G-as well as Fig. 11 and is held in-- that position by reason of the facts (c) thatthehydraulicpres sure on-its lower end is less" than the hydraulic pressure on its-upper end by the amount 0603f sioned by the presence'of the-spring 23',and- (b)- that the spring 43 operates to holdthe shifter valve 36in the position mentionede If the vehicle is-brought to 1 a stop, the motorpump device 2 will: no longer drive the reel to wind in the cable, because the cable-cannot then ordinarily be-Woundin butthere' willbe nothing which will occur in the controlling al aratus which would cause movement of-the shifter valve 36 to reduce thepressure imposed on the motor pumpdevice l and scthe cable will remain under undiminished tension while'the' vehicle is at a standstill. It will be noted that inthe position of the'shifter valve-fifi shown in Figs: 5;:6 and l 1, the-lower end of the projecting portion 41 engages the top surface-of the pIugA-B and the plunger portion isof the valve 49 contacts the end of the projectingv portion 41 and actsas: a val-ve associated with the passage 4152,1164; b'ecause'the spring 19 is'strong enough tomaintai-nthisccntact against the pressure for which the relief valve ll is set, no flow through the passage 4 downwardly or upwardly will be possible until the shifter valve is moved up'such a distance that contact between the plunger portion 15 of the valve 59 and the lower end'of-theprojecting portion ii of the shifter valve-is interrupted.

Now suppose that the-vehicle-is caused to move in the direction which will necessitate the unwinding of the cable" from the reel in -order for such motion to'takeplace. The tension of the-- cable will require the motcr-pump 'device l to" rotate" in such a? direction astopump fluid taken in through the conduit I l into the conduit 7, 6. This fluid will pass into the chamber it, but cannot pass the valve 22, and it also will" be unable to pass the shifter valve 36 in the lower position of that valve. Accordingly there will be an instantaneous building up of pressure below the shifter valve 36 to a value in exces of the pressure existing on the top of that valve supplemented by the strength of the spring 43, and the shifter valve will start to move upward. The valve 49 will be moved upward by the spring 19 as long as there is no contact between the head portion E of the valve 49 and the portion of the plug 48 above the bore 11. Thus there can be no flow of fluid from the space below the shifter valve to the space above it, and the greater pressure below this valve will be maintained until the shifter valve gets well underway and preferably moves upward to such a point that the groove All can connect the port 5| with the annular chamber 28 and with the conduit [3 and thus permit a relief of the pressure at the upper end of the shifter valve. After this relief in pressure takes place, it will require no great pressure below the shifter valve to complete its travel and to maintain it in raised position, and when the shifter valve reaches top position the fluid pumped by the motor-pump I will be permitted to pass through the opening 52 and past the lower set relief valve 65 into the port 59 and through annular chamber 28 into the conduit [3, but it will be noted that the pressure acting to maintain the shifter valve in raised position will still exceed the pressure tending to force it down again by reason of the fact that the force produced by the sprin 43 and the freely venting discharge of the pump 3 will not be equal to the pressure resulting from the presence of the relief valve 65 with its loading spring 66.

To repeat, the back pressure on the main pump is completely removed except for such resistance as friction of the liquid in the passages may involve, when the shifter valve is maintained in top position, and this shifter valve will be maintained in top position because of the greater pressure imposed on its lower end by reason of the presence of the relief valve 65 and its loading spring 66, this relief valve being adapted to maintain a pressure of, for example, 100 p. s. i. in the chamber 53. By reason of the structure described, the tension on the cable ID will be substantially reduced, and the reel may be turned backward, driving the motor-pump device 1 as a pump, with a much lower pressure in the line 6 than during the operation of the motor-pump device as a motor.

Now let it again be assumed that the vehicle stops. The motor-pump device 1 no longer acts as a pump and no longer delivers fluid through the conduit 6. Since the valve 49 is not sealing the passage 47, in the raised position of the shifter valve, the latter will move downwardly freely upon the cessation of the pumping of fluid into the chamber [8, until the lower end of the projecting portion i! contacts the plunger portion T6 of the valve 49, and at the time the communication between the port 5! and the line it has, with a desirable proportioning of the parts, been interrupted, with the result that the pressure above the shifter valve will build up to the full amount called for by the setting of the relief valve 1|. Thus, even though the shifter valve did not go all the way down to its position shown in Figs. 5 and 6, the pressure would build up to the setting of the relief valve H and the cable would be placed under tension, ready for imme diate winding in if the vehicle starts to move in a direction in which winding up of the cable will be requisite. If the passage 46, 41 were sealed off slightly before the communication between the passages 51' and 28 was completely interrupted, still, the throttling of the pump discharge could be counted on to cause a sufiicient increase in the pressure above the valve 36 to cause the latter to move down to its bottom position.

It will be observed that the valve 49 prevents flow of fluid longitudinally through the valve Eli-from the lower to the higher end thereofuntil the valve has reached a position in which the groove 49 between its spools comes into communication with the passage 5|, and it may further be noted that the strength of the spring I9 is sufficient to cause the plunger '16 to maintain contact with the lower end of the shifter valve and seal the passage through the latter so long as the shifter valve is within the range of movement of the valve :19. In passing it may be noted that fluid locking of the valve 49 is prevented by the provision of adequate clearances around its head l'5 and plunger portion 16.

One important feature of the arrangement so far described is the provision of means which seals a passage through the shifter valve as long as the latter is below positions in which the passages 5i and 28 are not in communication with each other, and, more broadly, there is presented by the invention a shifter valve having chambers above and below it and with means provided for the interconnection, through a restricted passage, of such chambers in predetermined positions of the shifter valve, with said passage automatically sealed when the shifter valve is below positions in which communication between the grooves 21 and 28 exists. So viewed, it will be appreciated that in its broader aspects my invention is also present in the modification of Figs. 12 and 13, and also in the modification of Figs. 14 and 15, now to be described.

Referring first to the former figures (Figs. 12 and 13) it will be noted that the valve 49 has a head which has a close sliding fit with the bore is extending through the shifter valve 36, except at the lower enlarged end 86 of such bore, where there is such an increase in diameter that when the head 85 lies wholly in the enlarged end 85, fluid can pass freely through the passage or bore 46' and the enlarged lower end thereof. The valve 49' may be made of uniform diameter, instead of having a head larger than its supporting stem The longitudinal extent of the enlarged bore 8'6 and the position of the upper end of the head 85 will be so determined that communication will be established between the chambers 25 and 30, desirably, just as connection is established between the grooves 21 and 28. The valve 49' is secured, in this embodiment, to a screw plug 81, threadedly secured in the bottom plug 88. As may be seen from Fig. 12, there is no substantial passage of fluid from the chamber 36 to the chamber 28 when the shifter valve is in its lowermost position of Fig. 12, or before the passage 5] and the groove 28 are interconnected, but in the upper position of the shifter valve, the chambers 30 and 28 freely communi cate with each other through the bore 46.

In both of the forms of the invention so far described in some detail, ready adjustment of the positions of the valves, respectively, 49 and 49 is possible, and the passages which are adapted to connect the chambers 26 and 3B traverse the shifter valves. It ispossible, however, as shown sage which extends longitudinally therethrough I,

and obstructing said passage during certain intermediate portions of the movements of said device.

5. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn off of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to efiect winding of said cable and to be driven by said reel as cable is pulled off of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to efiect reel drive, a one-way connection for the flow of fluid from said pump to said motor-pump device, means for conducting fluid after it has done work in said motor-pump device back to said source, a relief connection between said one- 7 way connection and said source having a relief valve therein set to open upon the attainment of a relatively high pressure in said one-way connection, another relief connection arranged between said one-way connection and said source and having a relief valve therein set to open upon subjection to a relatively lower pressure, and means for preventing flow from said oneway connection to said second relief connection when said motor-pump device is driving said reel including a longitudinally bored valve device movable by the discharge pressure of said motorpump device when the same is acting as a pump and having a controlling valve, relative to which it is movable, for rendering the bore through said valve device inoperative to affect its movements in predetermined portions of its path including portions intermediate the ends of the latter.

6. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn off of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to be driven by said reel as cable is pulled off of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to effect reel drive, a check valved one-way connection for the flow of fluid from said pump to said motor-pump device, means for conducting fluid after it has done work in said motor-pump device back to said source, a relief connection between said one-way connection and said source having a relief valve therein set to open upon the attainment of a relatively high pressure in said one-way connection, another relief connection arranged between said one-way connection and said source and having a relief valve therein set to open upon subjection to a relatively lower pressure, and means for preventing flow from said one-way connection to said second relief connection when said motor-pump device is driving said reel including a valve device traversed by an axial passage and. having oppositely facing areas in continuous communication with said one-way connection at opposite sides of the check valve therein, said valve device traversed by an axial passage having associated with it, for controlling said axial passage, a valve relative to which said valve device is movable and which valve projects into the path of movement of said valve device and has an inner end between and spaced from the end limits of said path.

'7. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn off of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to be driven by said reel as cable is pulled off of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to effect reel drive, a conduit to which said pump discharges, a conduit connected to said motor-pump device and alternatively operative to conduct fluid received from said flrstconduit tosaid motor-pump device to drive the latter as a motor and to serve as a discharge line from said motorpump device when the latter is driven by said reel and acts as a pump, a conduit connecting said motor-pump device with said source and alternatively serving as an exhaust line when said motor-pump device drives said reel and at least in part as a suction line When said motor-pump device is driven by said reel, a conduit connecting said first and second conduits, conduit means for connecting said first conduit to said source having a relief valve therein set at a relatively high relief pressure, a conduit means for connecting said first conduit to said source having between its ends a valve shiftable to open and close the same, and conduit means for connecting said second conduit to said source having a relief valve therein set at a relatively low relief pressure and also controlled by said shiftable valve, said shiftable valve being perforate from end to end and having associated with it, to control flow between its ends, a valve relative to which it is movable to control such flow and which valve projects into the path of movement of said shiftable valve and has an inner end spaced from the end limits of such path.

8. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn ofi of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to be driven by said reel as cable is pulled off of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to effect reel drive, a conduit to which said pump discharges, a conduit connected to said motor-pump device and alternatively operative to conduct fluid received from said first conduit to said motorpump device to drive the latter as a motor and to serve as a discharge line from said motorpump device when the latter is driven by said reel and acts as a pump, a conduit connecting said motor-pump device with said source and a1- ternatively serving as an exhaust line when said motor-pump device drives said reel and at least in part as a suction line when said motor-pump device is driven by said reel, a conduit connecting said first and second conduits and having a va e as ci t d th rewith fo p ti g flow,

therethrough from the second conduit to the first, conduit means for connecting said first con duit to said source having a relief valve therein set at, a relatively high relief pressure, conduit means for connecting said first conduit to said :source having between its ends a valve shiftable to open and close the same, and conduit means for connecting said second conduit to said source having a relief valve therein set at a relatively low relief pressure and also controlled bysaid shiftable valve, said shiftable valve having oppositely facing surfaces continuously connected in communication, one with said first conduit, and; the other with said second conduit and connested; in communication with each other when, but only substantially as, said valve attains to a 'PQ ition to open said conduit means for connecting said first conduit with said source.

In combination, a windin eel mounted upon. a, vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn off of said ree ep n n u on he direction i hicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to'be driven by said reel as cable is pulled oif the latter, a source of hydraulic fluid, a pump connected to sa d so ce o w fluid therefrom and to supply fluid to drive said motor- :P mP device as a motor to fiect r drive, a du'i't to which Said pump discharges, a conduit connected to said motor-pump device and alternativel opera ve to ndu d r c iv d from .said first conduit .to said motor-pump device to .clr'ive thelatter as a motor and to serve as a dis- ,1

chargeline from said motor-pump device when the latter is. driven y said re l nd. s as a pump, a conduit c nn tin sa d m r l p evice with said source and alternatively serving as an, exhaust line when said motor-pump device L drives said reel and at least in part as asuction line when said. motor-pump device is driven by said .reel, a conduit connecting said first and second conduitsand having a valve associated therewith for preventin flow 'therethrqll ll from the second conduit to the first, conduit means for connecting said firstconduit to said source having a relief valve therein set at a relatively high reliefpressu e,-co duit me ns for onne ti ss i first Conduit to said source having between its i sends, a valve shiftable to vopen and close the same, and conduit means for connecting said secand conduit to said source having a relief valve therein set at a relatively low relief pressure and also controlled by said shiftable valve, said ,s'hiftable valve having oppositely facing surfaces continuously "connected in communication, one with said first conduit, and the other with said second conduit and having associated therewith means for providing a restricted communication between-said surfaces, a spring-for biasingsaid valvein the direction in which the-surface sub jected to the pressure in said second conduit faces, and means for cutting off the restricted communication between said surfaces so long as sald'shiftable valve is cutting off communication between said first conduit andrsaid source.

10. In a cable reeling mechanism adapted to ,SHPDIY power to a moving vehicle, a Windingreel :adapted to have a cable wound upon it,;a -m otorpump device operable as a motor to drive gsaid :reel inadirection to wind cablezthereon, aifiuid pump, a pressure line connecting said pump to said motor-pump device, said motor-pump device being drivable by said winding reel to cause the 14 same to operate as a pump when cable ispulled off of the reel, neansfor imposing on-said motor-pump device a predetermined supply pressurewhen itis operating as a motorand a lower back pressure when it is being driven by the reel and acting as-a pump, including a valve-ele- ;ment movable to diflerent positions to eifect said changes in pressure a-nd actuated by fluid pumped by said motor-pump device when the latter is driven bythe reel, and means also including said valve element for substantially wholly relieving the back pressure imposed on said 'fiuid pump when cable is being pulled off of the reel, said valve element having associated therewith means for permitting the passage of fluid from one end to the other thereoi and a separate valve relative to which said valve element is movable during at least a part or its "own movement -for prevent- ;ing fluid flow through said fluid passage permitting means in --certain';positions of said valve element other than said diiferent positions, "said separate valve 'having means for yield ingly supporting it for movement through a distance less than therange of movement ofsaid-valve elei amr 11. In a cable reeling mechanism adapted to supply power to a moving vehicle, -a winding reel adapted to have acable wound'upon it, a motor-- pump device operable as a motor to drive said reel in a direction to wind cable thereon, a fluid pump, a pressure line connecting said pump to said motor-pump device, said motor-pump device being drivable by said winding recite-cause the same to operate as a pump when cable is pulled-off of the reeLmeans *for imposing -'on said motor-pump device a predetermined supply pressure when it is operating as amotor and a lower back pressure when it is' being driven by the reel 'one-endto theothe-rthereof and a-separate valve relative to which said :valve'element is movable during at least a part of its own movement for preventing -fiuid -flow through said fiuid passage permitting means in certain positions of said valve element other than-said diiferentpositions,

said'separate valve having a portion receivable, in certain positions of said valve element, in said means for permitting the passage of fluid from one end to 'the'other of said valveelement, :to prevent =fiow through said means.

12.'In a cable reeling mechanism adapted to supply power to a moving-vehicle, a winding reel adapted-to have a cable Wound upon it, i a motor- -pump-device operable-asa motor to drivesaid reel in a-direction=to :windcable thereon, afluid pump, a pressure line-connecting said pump to 'said motor-pumpdevice, said motor-pump devic "being drivable *by said winding reel to cause the same-t0 .Operate as a pump when-cable is-pulled Off 'ofthe reel,means'ior imposingon said motorpurnp device a predetermined supply pressure ,when'itjis pperating as a mgtor-and a'lower back pressure w en t i 'heins driven-b he reel a acting as a pump, including a valve element movable to diiferent positions to effect said changes in pressure and actuated by fluid pumped by said motor-pump device when the latter is driven by the reel, and means also including said valve element for substantially wholly relieving the back pressure imposed on said fluid pump when cable is being pulled off of the reel, said valve element having associated therewith means for permitting the passage of fluid from one end to the other thereof and a separate valve relative to which said valve element is movable during at least a part of its own movement for preventa ing fluid flow through said fluid passage permitting means in certain positions of said valve element other than said different positions, said valve element and separate valve having portions coacting with each other in certain positions only of said valve element to cut ofl fluid flow through said means for permitting the passage of fluid.

13. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn off of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to be driven by said reel as cable is pulled ofi of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to effect reel drive, a check valved one-way connection for the flow of fluid from said pump to said motorpump device, means for conducting fluid after it has done work in said motor-pump device back to said source, a relief connection between said one-way connection and said source having a relief valve therein set to open upon the attainment of a relatively high pressure in said oneway connection, another relief connection arranged between said one-way connection and said source and having a relief valve therein set to open upon subjection to a relatively lower pressure, and means for preventing flow from said one-way connection to said second relief connection when said motor-pump device is driving said reel including a Valve device traversed by an axial passage and having oppositely facing areas in continuous communication with said one-way connection at opposite sides of the check valve therein and having further a valve associated with it, projecting into its path from one end of the latter and relative to which it is movable, for controlling said axial passage, and maintaining it closed until said valve device has moved a substantial distance away from said one end of said path.

14. In combination, a winding reel mounted upon a vehicle for movement therewith and adapted to have a cable wound thereon and to wind in said cable or to have the same drawn oif of said reel depending upon the direction of vehicle movement, a motor-pump device connected to said reel to drive the latter to effect winding of said cable and to be driven by said reel as cable is pulled oif of the latter, a source of hydraulic fluid, a pump connected to said source to draw fluid therefrom and to supply fluid to drive said motor-pump device as a motor to eifect reel drive, a first conduit to which said pump discharges, a second conduit connected to said motor-pump device and alternatively operative to conduct fluid received from said first conduit to said motor-pump device to drive the is latter as a motor and to serve as a discharge line from said motor-pump device when the latter is driven by said reel and acts as a pump, a conduit connecting said motor-pump device with said source and alternatively serving as an exhaust line when said motor-pump device drives said reel and at least in part as a suction line when said motor-pump device is driven by said reel, a conduit connecting said first and second conduits, conduit means for connecting said first conduit to said source having a relief valve therein set at a relatively high relief pressure, conduit means for connecting said first conduit to said source having between its ends a valve shiftable to open and close the same, and conduit means for connecting said second conduit to said source having a relief valve therein set at a relatively low relief pressure and also controlled by said shiftable valve, said shiftable valve being perforate from end to end and having associated with it a valve projecting into its path from one end of the latter and relative to which it is movable to control flow between its ends and to preclude such flow until said shiftable valve has moved a predetermined distance from said one end.

15. In a cable reeling mechanism adapted to supply power to a moving vehicle, a winding reel adapted to have a cable wound upon it, a motorpump device operable as a motor to drive said reel in a direction to wind cable thereon, a fluid pump, a pressure line connecting said pump to said motor-pump device, said motor-pump device being rotatable by said winding reel to cause the same to operate as a pump when cable is pulled off of the reel, means for imposing on said motor-pump device a predetermined supply pressure when it is operating as a motor and a lower back pressure when it is being driven by the reel and acting as a pump, including a valve element movable to different positions to eiiect said changes in pressure and actuated by fluid pumped by said motor-pump device when the latter is driven by the reel, and means also including said valve element for substantially wholly relieving the back pressure imposed on said fluid pump when cable is being pulled off of the reel, said valve element having associated therewith means for permitting the passage of fluid from one end to the other thereof and a separate valve relative to which said valve element is movable during at least a part of its own movement for preventing fluid flow through said fluid passage permitting means in certain positions of said valve element other than said different positions, said separate valve projecting into the path of said valve element from one end of said path and precluding flow through said means for permitting the passage of fluid from one end to the other of said valve element save when said valve element has moved a substantial distance from said end of its path.

RICHARD J. HOPKINS.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 2,220,479 De Bell Nov. 5, 1940 2,395,302 Slomer Feb. 19, 1946 2,406,120 Wirth Aug. 20, 1946 2,467,238 Slomer Apr. 12, 1949 

